AHI the same at different pressures need advise

Hi everybody (hello Pugsy), it has been years I haven't come here.

I'm trying to help a friend to return to use CPAP. She was given a CPAP years ago because she snore and "supposely" she didn't have sleep apnea.
It had been a year she wasn't using her machine because she complained the cpap made her to have "a lot of secretions". Then she decided to use a mandibular advancing device. I didn't saw that as a good idea.
I plugged her to my oximeter and I discovered she had desaturations and worst when using the mandibular device.
Now, I proposed her to plug her to one of my S9 autoset and see if it was true she needed a CPAP. She also bought a new Swift FX for her.
The weird thing I cant understand is I started with min 6psi max 8 psi she get AHI around 1.57 ans also 0.67 once and 95%pressure was 8 (her machne was completely dead when I tried to start it to find her old pressure, F&P, she thought it was maybe 10 not sure). I changed pressure to 7min 9 max, she had same AHI results, some low other around 1.8 and 95%pressure was 9. Again I changed pressures 8min 10.4 max, same AHI results and 95%pressure at 10.4.
She decided to change pressure without telling me (she becomes independent LOL) 8min 11.2 max and last night she had AHI 1.27 with 95%pressure 11.2psi.
The leaks are not an essue, she doesn't snores, she is sleeping 8 hours only one wake up, I can't understand how can she have 0.65 and 1.75 at pressure of 8 and the same at 11 .2 psi. I had told her the machine was going to give her only the pressure she needed but she is always giving the maximum set. I know 1.75 could be not bad at all but I wanted to try to get her with an AHI around 1 not too high. Could somebody help me to see what I have lost here? Thanks very much.
Rosie

Hi Rosie,
Good to see you again.

Quit trying to find the "perfect" every night pressure settings. It will drive a person crazy.

We don't sleep the same each night and it's going to vary and sometimes varies a lot.
Last night my AHI was close to 2.0 when all this past week it has been below 1.0 and one time it was just one event shy of a "perfect" 0.0 AHI>
I haven't changed my settings in probably a couple of years but my sleep changes every night.

If she's sleeping good and feeling good and no more desats.....leave things well enough alone.

Explain to your friend that the 95% number doesn't mean much. It just means that a person was at OR BELOW that number for 95% of the night. It is NOT where a person spends 95% of the night. It is NOT any sort of magical number for anything.

Experiments with settings should allow at least a week at the same settings preferably 2 weeks unless results are horrible for some reason or another.

Hi Pugsy,

Cpaptalk refused to let me login, I needed to change my user to rosacer is back,

I'm happy you are still her, it has been I thing 7 years I was not around.

Thank you for the feedback, I was thingking to tell her to put the machine as CPAP at 8psi for a couple of days an let see what it gives because in any case that seemed to be not bad some times. She told she felt rested, but to me it's a mystery her results. I thing a CPAP at 8 is way better than her mandibular thingy.

Hello Pugsy

This thing is making me all kind of trouble, it forbided me to login, I created a new account and now it tells I'm not allowd to send private messages, what a pain. I tried to comme in as a guesst and it didn't work neither, you dont allow guesses now, anyway

I was thinkling to set my friend at constant pressure at 8 or 9 psi for a couple of days because it will be better than her advance mandibular device and she had not too bad results when she was at that pressure.
I'm very curius how it is she alwast takes all the pressure but the AHI stays the same, I had never seen that.
Here we have to wait monts maybe a year in some cases top see a MD specialist, it is no option to see a pneumologist, on top of that we live in the country, I moved 1.5 years ago from the big town. I will try to communicate privately with you to give news.
Rosie